Integrated Frequency Allocation and User Assignment in Multimodal Transit Networks

This paper presents an integrated solution method to the frequency-setting problem using optimization and assignment simulation. With a bilevel solution framework, an optimization problem is run at the upper level under the assumption that the total transit demand is fixed. The objective is to maximize wait time savings under the budget, fleet size, vehicle load, and policy headway constraints. At the lower level, an assignment and simulation algorithm is run; the algorithm models the demand response to the new frequency setting and transmits updated ridership and flow values to the upper level. The procedure is repeated until the improvement in the wait time savings converges. The platform is tested on the Chicago Transit Authority network in Illinois for the morning peak. The wait time savings in this experiment are converging and are found to be comparable with the results of a stand-alone frequency-setting algorithm that finds optimal solutions. Results are comparable with the optimal results of a stand-alone platform introduced in another study that modeled the demand response locally by using elasticities as opposed to networkwide modeling using assignment. The integrated platform can be used for medium-term strategic and long-term planning decisions.

[1]  Hani S. Mahmassani,et al.  Stretching resources: sensitivity of optimal bus frequency allocation to stop-level demand elasticities , 2015, Public Transp..

[2]  Avishai Ceder,et al.  BUS FREQUENCY DETERMINATION USING PASSENGER COUNT DATA , 1984 .

[3]  F. Salzborn.  Optimum Bus Scheduling , 1972 .

[4]  Michael Florian,et al.  Optimizing frequencies in a transit network: a nonlinear bi-level programming approach , 1995 .

[5]  Hani S. Mahmassani,et al.  Equivalent gap function-based reformulation and solution algorithm for the dynamic user equilibrium problem , 2009 .

[6]  Nigel H. M. Wilson,et al.  Bus network design , 1986 .

[7]  Peter G Furth,et al.  TRANSIT ROUTING AND SCHEDULING STRATEGIES FOR HEAVY-DEMAND CORRIDORS (ABRIDGMENT) , 1985 .

[8]  Hani S. Mahmassani,et al.  Dynamic Assignment-Simulation Methodology for Multimodal Urban Transit Networks , 2015 .

[9]  Michael Florian,et al.  Optimal strategies: A new assignment model for transit networks , 1989 .

[10]  Stefano Pallottino,et al.  Equilibrium traffic assignment for large scale transit networks , 1988 .

[11]  Hani S. Mahmassani,et al.  Hybrid route generation heuristic algorithm for the design of transit networks , 1995 .

[12]  Luca D’Acierno,et al.  The transit network design problem with elastic demand and internalisation of external costs: An application to rail frequency optimisation , 2011 .

[13]  Mark Hickman,et al.  Hyperpaths in Network Based on Transit Schedules , 2012 .

[14]  F. J. M. Salzborn,et al.  Scheduling Bus Systems with Interchanges , 1980 .

[15]  Hani S. Mahmassani,et al.  Planning and Design Model for Transit Route Networks with Coordinated Operations , 1998 .

[16]  Gordon F. Newell,et al.  Some Issues Relating to the Optimal Design of Bus Routes , 1979 .

[17]  Avishai Cede,et al.  Public Transport Timetabling and Vehicle Scheduling , 2002 .

[18]  H. Mohring.  Optimization and Scale Economies in Urban Bus Transportation , 1972 .

[19]  S. Pallottino,et al.  Hyperpaths and shortest hyperpaths , 1989 .

[20]  Hyunsoo Noh,et al.  Capacitated Schedule-Based Transit Assignment Using a Capacity Penalty Cost , 2013 .

[21]  L. Lin,et al.  A concordance correlation coefficient to evaluate reproducibility. , 1989, Biometrics.

[22]  Siv Schéele,et al.  A supply model for public transit services , 1980 .

[23]  Nigel H. M. Wilson,et al.  The allocation of buses in heavily utilized networks with overlapping routes , 1982 .

[24]  Modeling and Forecasting of Toll Revenues , 2013 .

[25]  Peter G Furth,et al.  SETTING FREQUENCIES ON BUS ROUTES: THEORY AND PRACTICE , 1981 .

[26]  Hani S. Mahmassani,et al.  Optimal Allocation of Service Frequencies over Transit Network Routes and Time Periods , 2013 .

[27]  Larry J. LeBlanc,et al.  Transit system network design , 1988 .

[28]  D K Smith,et al.  Numerical Optimization , 2001, J. Oper. Res. Soc..